keepass-ng 0.11.0

use aes::Aes256;
use cipher::{Array, typenum::U32};
use cipher::{BlockCipherEncrypt, KeyInit};
use sha2::{Digest, Sha256};

use super::CryptographyError;

pub(crate) trait Kdf {
    fn transform_key(&self, composite_key: &Array<u8, U32>) -> Result<Array<u8, U32>, CryptographyError>;
}

pub struct AesKdf {
    pub seed: Vec<u8>,
    pub rounds: u64,
}

impl Kdf for AesKdf {
    fn transform_key(&self, composite_key: &Array<u8, U32>) -> Result<Array<u8, U32>, CryptographyError> {
        let seed_arr = self.seed.as_slice().try_into().map_err(|_| cipher::InvalidLength)?;
        let cipher = Aes256::new(&seed_arr);
        let mut block1 = composite_key[0..16].try_into().map_err(|_| cipher::InvalidLength)?;
        let mut block2 = composite_key[16..].try_into().map_err(|_| cipher::InvalidLength)?;
        for _ in 0..self.rounds {
            cipher.encrypt_block(&mut block1);
            cipher.encrypt_block(&mut block2);
        }

        let mut digest = Sha256::new();

        digest.update(block1);
        digest.update(block2);

        Ok(digest.finalize())
    }
}

pub struct Argon2Kdf {
    pub memory: u64,
    pub salt: Vec<u8>,
    pub iterations: u64,
    pub parallelism: u32,
    pub version: argon2::Version,
    pub variant: argon2::Variant,
}

impl Kdf for Argon2Kdf {
    fn transform_key(&self, composite_key: &Array<u8, U32>) -> Result<Array<u8, U32>, CryptographyError> {
        // Disable Argon2 multithreading on wasm32 targets to avoid panics on platforms without thread support.
        let thread_mode = if cfg!(target_arch = "wasm32") {
            argon2::ThreadMode::Sequential
        } else {
            argon2::ThreadMode::Parallel
        };

        #[allow(clippy::cast_possible_truncation)]
        let config = argon2::Config {
            ad: &[],
            hash_length: 32,
            lanes: self.parallelism,
            mem_cost: (self.memory / 1024) as u32,
            secret: &[],
            thread_mode,
            time_cost: self.iterations as u32,
            variant: self.variant,
            version: self.version,
        };

        let key = argon2::hash_raw(composite_key, &self.salt, &config)?;

        key.as_slice().try_into().map_err(|_| cipher::InvalidLength.into())
    }
}

/*
pub(crate) fn transform_key_argon2(
    composite_key: &GenericArray<u8, U32>,
) -> Result<GenericArray<u8, U32>> {
    let version = match version {
        0x10 => argon2::Version::Version10,
        0x13 => argon2::Version::Version13,
        _ => return Err(DatabaseIntegrityError::InvalidKDFVersion { version: version }.into()),
    };
}
*/